1. Field of the Invention
This invention relates to components of apparatus for film making by a vapor deposition method such as a sputtering, chemical vapor deposition, or vacuum deposition and method for manufacturing the same.
2. Description of the Prior Art
LSI (Large Scale Integrated Circuit), LCD (Liquid Crystal Display), Magneto-optical Disk, Hard Disk and the like are manufactured by a thin film making technique of materials suited for aimed object on substrate. In film making operation, so called "fine particles" that have, for example, several micron meters in diameter, occasionally attach on the substrate, causing problems, for example, short circuit of wiring on the substrate in case of LSI, resulting in low yield of products and losing product reliability in the market.
To this kind of problems, many necessary measures have been taken. In film making process by sputtering, for example, the problems of fine particles carried over by transfer system, or generated from target materials, have almost been solved. At present, it is considered that the existing fine particles are caused by deposits of film-forming material on components of film making apparatus, in other words, peeling and falling off of deposits and by scatter fine particles during film making operation.
Such components of apparatus are a shutter, a shielding plate, a substrate holder, a mask, and so on. But frequent cleaning of film making apparatus before deposits peeling-off and fine particles scattering leads to decrease of operation time.
Some kinds of techniques to dissolve the above problems have been disclosed at Japanese Patent Opening Gazette No. 87356/1991, No. 87357/1991, No. 166361/1991 and No. 166362/1991. In those, the surface of the components of film making apparatus are covered by metal foil embossed, or metal foil corrugated. Electrolytic refined copper foils embossed are already on the market, and they are fixed by spot welding or riveting, covering the surface of the components. And it is disclosed that the copper foil embossed is effective to keep deposit of film forming materials on itself, because the copper foil relaxes peeling stress between the copper foil and the deposit by means of deforming itself before peeling-off occurs. Electrolytic refined copper foil embossed is disclosed to be effective to prevent the deposit from peeling off, but it cannot be used over again, and it is troublesome to detach the used one and fix the new one at every intervals of operation. Furthermore, exceeding thickness of deposit causes the copper foil to tear, exposing surface of components.
Another technique is shot-blasting or glass-beads blasting to surface of components to clean the surface and increase the total area of surface, increasing adhesion strength of deposit, but its effect is not enough to prevent the deposits from peeling off. And due to repeated blasting, heat is accumulated in the components, occasionally resulting in cracking of the components. Differently another technique is coating by thermal spray (molten metal spray) on shot blasted base metal. For example, coating by thermal spray of aluminum, which is easy to be deformed, on shot-blasted surface of aluminum alloy base plate as shown in FIG. 1 is widely used. This technique is rational in the point that peeling stress of the deposit of film-forming material is relaxed by means of deformation of the coating itself. But, about 0.5 mm in thickness of deposit of film forming material like Tantalum which has large degree of peeling stress, leads to peeling between the coating by thermal spray of aluminum and the aluminum alloy base plate. As mentioned above, there is no effective technique to prevent deposit from peeling off. Furthermore, as described below, components coated by thermal spray has the defect that gases occluded in the coating causes outgassing from the components during film making operation.